1. Field of the Invention
The present invention relates to apparatus for and a method of recording data on an optical disc, wherein image data are recorded on an optical disc 10 formatted under the Compact Disc (CD) standard, and more particularly to such an apparatus and a method including verifying an optical disc to determine presence/absence of a defect such as a crack on the optical disc.
2. Description of the Background Art
Compact Disc ROMs (CD-Rs) implemented on optical discs provided under the Compact Disc Standard (Orange Book Standard) regulated by Sony and Philips' are directed to, hitherto, only the type for one-time recording in which a session of data is recorded at a time, even though there are found a few differences in processing, such as pressing from a pre-master and a pre-recording by a one-time recording. The progress of 25 the technology permits the use of a type of disc available for post-writing such as an additional writing or recording and a rewriting. These types of conventional discs, so-called one-time writing or write-once ROM types, are subjected to recording by software suppliers 30 and then forwarded under a strict quality control. Consequently, it may be that the discs have defects such as cracks formed during the first use.
The post-writing type of photo CDs, regulated by Kodak and Philips', however may be subjected to rewriting of image data by users or laboratories in the event that there remains a vacant or unused area recordable on the discs once recorded, or recorded data may be desired to be erased to rewrite or substitute therefor new data. Image data may be recorded on photo CDs in the form of hierarchical storage of high resolution digital images in a multiuse environment. Such a hierarchical storage system is taught in U.S. Pat. No. 4,969,204 to Melnychuck et al.
While recording of the image data is performed, in general, by a CD writer in a professional laboratory on discs used once, it may happen that the post-writing of new data is not normally performed in the event that such discs are subjected to a defect, such as a crack and extreme dirt thereon, occurring in the process of the user's playing back operation, saving or storage, transportation and the like. Further, there is a possibility that the data recorded on such discs having a defect will not be able to be played back in the future. Since the conventional CD writer is constructed taking account of only the one-time recording type of compact disc, it is difficult under the above-mentioned bad conditions to additionally write new data onto such a disc without the possibility of destroying data already recorded on the disc.
If recording is tried by a conventional CD writer on a compact disc having the bad conditions mentioned above, a tracking error may occur which will be a cause of not only errors in recording of new data but also destroying even the former data already recorded. If the former data is not destroyed, the disc will include data of high data error rate, since the recording is performed on the disc having defects. Further, there is a fear that the data recorded in such discs having defects will not at all be able to be played back in future, and thus it is necessary to cope with this problem.